@charset "UTF-8";

html{
    width: 100vw;
    height: 100%;
    font-family: "Noto Sans JP", sans-serif;
    color: #ffffff;
    scroll-behavior: smooth;
}

#brk{
    position: absolute;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.5);
    background-attachment: fixed;
    backdrop-filter: blur(8px);
}


body::before{ 
content:"";
display:block;
position:fixed;
top:0;
left:0;
z-index:-1;
width:100%;
height:100vh;
background-repeat:no-repeat;
background-position:50% 100%;
background-image:url(../img/music.gif);
background-size:cover;
}

.fixed{
    width: 100%;
    margin: auto;
}

header{
    filter: drop-shadow(0px 0px 10px rgba(0, 0, 0, 0.4));
    width: 100%;
    z-index: 999;
    max-width: 500px;
    margin: auto;
    top: 0;
    position: fixed;
}

.page{
    position:absolute;
    display: inline-block;
    width: 15.3px;
    height: 26.6px;
}

.page::before,
.page::after {
    content: "";
    position: absolute;
    top: calc(50% - 2px);
    width: 20px;
    height: 3px;
    background-color: #ffffff;
    transform-origin: 1px 50%;
    }

.page::before {
    transform: rotate(45deg);
}

.page::after {
    transform: rotate(-45deg);
}

article{
    font-size: 0.8rem;
    line-height:1.5;
    letter-spacing: 0.2cap;
}

h3{
    font-size: 0.9rem;
}


@media print, screen and (min-width: 501px) {
    .page{
        top:40px;
        left:10vw;
    }

    #main{
        margin-top: 100px;
        margin-bottom: 100px;
        width: 100vw;
    }

    h2{
        font-size: 1.5rem;
        font-weight:900;
        letter-spacing: -0.1cap;
    }

    h3{
        font-size: 1rem;
    }
    
    #info_area{
        width: 90%;
    }
    
    .contents{
        width: 64vw;
        margin: 0 auto;
        padding-bottom: 20px;
        border-bottom: #ffffff solid 1px;
    }
    
    .contents article{
        margin-bottom: 20px;
    }

    .music{
        display: block;
        margin: auto;
        width: 64vw;
    }

    .title{
        width: 100%;
        margin: 30px auto 20px auto;
    }

    #page-top {
        position: fixed;
        bottom: 24px;
        right: 24px;
        width: 48px;
        height: 48px;
        text-decoration: none;
        background-color: rgba(0, 0, 0, 0.402);
        border: #fff solid 2px;
        display: block;
        text-align: center;
        border-radius: 24px;
        opacity: 0;
        transition: opacity 0.4s ease-in;
    }
    
    .pagetop__arrow {
        height: 20px;
        width: 20px;
        border-top: 3px solid #ffffff;
        border-right: 3px solid #ffffff;
        transform: translateX(60%) translateY(80%) rotate(-45deg);
    }
    
      /* fadeinクラスがついた時だけ表示する */
    #page-top.fadein {
        opacity: 1;
    }
    
    
}

@media screen and (max-width: 500px){
    .page{
        top: 20px;
        left:20px;
    }

    #main{
        margin-top: 100px;
        margin-bottom: 100px;
    }

    h2{
        font-size: 1.3rem;
        font-weight:900;
        letter-spacing: -0.1cap;
    }
    
    #info_area{
        width: 100vw;
    }

    .contents{
        width: 90%;
        margin: 0px auto 0 auto;
        padding-bottom: 20px;
        border-bottom: #ffffff solid 1px;
    }

    .contents article{
        margin-bottom: 20px;
    }

    .music{
        display: block;
        width: 80vw;
        margin: auto;
    }


    .title{
        margin: 30px auto 20px auto;
    }

    #page-top {
        position: fixed;
        bottom: 19px;
        right: 19px;
        width: 43px;
        height: 43px;
        text-decoration: none;
        background-color: rgba(0, 0, 0, 0.402);
        border: #fff solid 2px;
        display: block;
        text-align: center;
        border-radius: 24px;
        opacity: 0;
        transition: opacity 0.4s ease-in;
    }
    
    .pagetop__arrow {
        height: 15px;
        width: 15px;
        border-top: 3px solid #ffffff;
        border-right: 3px solid #ffffff;
        transform: translateX(80%) translateY(100%) rotate(-45deg);
    }
    
      /* fadeinクラスがついた時だけ表示する */
    #page-top.fadein {
        opacity: 1;
    }

}